// 实现这个项目的构建任务
const { src, dest, parallel, series, watch } = require('gulp')
const plugins = require('gulp-load-plugins')()
const sass = require('gulp-sass')(require('node-sass'))
const bs = require('browser-sync').create()
const style = ()=>{
    return src('src/assets/styles/*.scss', {base: 'src'})
            .pipe(sass({ outputStyle: 'expanded' }))
            .pipe(dest('temp'))
            .pipe(bs.reload({ stream: true }))
}
const script = ()=>{
    return src('src/assets/scripts/*.js', {base: 'src'})
            .pipe(plugins.babel({
                presets:['@babel/preset-env']
            }))
            .pipe(dest('temp'))
            .pipe(bs.reload({ stream: true }))
}
const page = ()=>{
    return src('src/*.html', {base: 'src'})
            .pipe(plugins.swig({ data: {}, defaults:{cache: false} }))
            .pipe(dest('temp'))
            .pipe(bs.reload({ stream: true }))
}
const images = ()=>{
    return src('src/assets/images/**', {base: 'src'})
            .pipe(plugins.imagemin())
            .pipe(dest('dist'))
}
const fonts = ()=>{
    return src('src/assets/fonts/**', {base: 'src'})
            .pipe(plugins.imagemin())
            .pipe(dest('dist'))
}
const extra = ()=>{
    return src('public/**', { base: 'public' })
            .pipe(dest('dist'))
}
const useref = ()=>{
    return src('temp/*.html', { base: 'temp' })
            .pipe(plugins.useref({ searchPath: ['temp', '.'] }))
            .pipe(plugins.if(/\.js$/, plugins.uglify()))
            .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
            .pipe(plugins.if(/\.html$/, plugins.htmlmin({ collapseWhitespace: true, minifyJS: true, minifyCSS: true })))
            .pipe(dest('dist'))
}
const clean = ()=>{
    return src('dist/*')
            .pipe(plugins.clean())
}
const compile = parallel( style, script, page )
const build = series(clean, parallel(series(compile, useref), extra, images, fonts))
const serve = ()=>{
    watch('src/assets/styles/*.scss', style)
    watch('src/assets/scripts/*.js', script)
    watch('src/*.html', page)
    watch([
        'src/assets/images/**', 
        'src/assets/fonts/**',
        'public/**'
    ], bs.reload)
    bs.init({
        notify: false,
        port: 2021,
        // files: 'dist/**',
        server:{
            baseDir: ['temp', 'src', 'public'],
            routes: {
                '/node_modules' : 'node_modules'
            }
        }
    })
}
const develop = series(build, serve)

module.exports = {
    clean,
    build,
    develop
}